Example #1
0
// Ewald::Recip_ParticleMesh()
double Ewald_ParticleMesh::Recip_ParticleMesh(Box const& boxIn)
{
  t_recip_.Start();
  // This essentially makes coordsD and chargesD point to arrays.
  Mat coordsD(&coordsD_[0], Charge_.size(), 3);
  Mat chargesD(&Charge_[0], Charge_.size(), 1);
  int nfft1 = nfft_[0];
  int nfft2 = nfft_[1];
  int nfft3 = nfft_[2];
  if ( DetermineNfft(nfft1, nfft2, nfft3, boxIn) ) {
    mprinterr("Error: Could not determine grid spacing.\n");
    return 0.0;
  }
  // Instantiate double precision PME object
  // Args: 1 = Exponent of the distance kernel: 1 for Coulomb
  //       2 = Kappa
  //       3 = Spline order
  //       4 = nfft1
  //       5 = nfft2
  //       6 = nfft3
  //       7 = scale factor to be applied to all computed energies and derivatives thereof
  //       8 = max # threads to use for each MPI instance; 0 = all available threads used.
  // NOTE: Scale factor for Charmm is 332.0716
  // NOTE: The electrostatic constant has been baked into the Charge_ array already.
  //auto pme_object = std::unique_ptr<PMEInstanceD>(new PMEInstanceD());
  pme_object_.setup(1, ew_coeff_, order_, nfft1, nfft2, nfft3, 1.0, 0);
  // Sets the unit cell lattice vectors, with units consistent with those used to specify coordinates.
  // Args: 1 = the A lattice parameter in units consistent with the coordinates.
  //       2 = the B lattice parameter in units consistent with the coordinates.
  //       3 = the C lattice parameter in units consistent with the coordinates.
  //       4 = the alpha lattice parameter in degrees.
  //       5 = the beta lattice parameter in degrees.
  //       6 = the gamma lattice parameter in degrees.
  //       7 = lattice type
  pme_object_.setLatticeVectors(boxIn.BoxX(), boxIn.BoxY(), boxIn.BoxZ(),
                                boxIn.Alpha(), boxIn.Beta(), boxIn.Gamma(),
                                PMEInstanceD::LatticeType::XAligned);
  double erecip = pme_object_.computeERec(0, chargesD, coordsD);

  t_recip_.Stop();
  return erecip;
}
Example #2
0
/** The LJ PME reciprocal term. */
double Ewald_ParticleMesh::LJ_Recip_ParticleMesh(Box const& boxIn)
{
  t_recip_.Start();
  int nfft1 = nfft_[0];
  int nfft2 = nfft_[1];
  int nfft3 = nfft_[2];
  if ( DetermineNfft(nfft1, nfft2, nfft3, boxIn) ) {
    mprinterr("Error: Could not determine grid spacing.\n");
    return 0.0;
  }

  Mat coordsD(&coordsD_[0], Charge_.size(), 3);
  Mat cparamD(&Cparam_[0], Cparam_.size(), 1);

  //auto pme_vdw = std::unique_ptr<PMEInstanceD>(new PMEInstanceD());
  pme_vdw_.setup(6, lw_coeff_, order_, nfft1, nfft2, nfft3, -1.0, 0);
  pme_vdw_.setLatticeVectors(boxIn.BoxX(), boxIn.BoxY(), boxIn.BoxZ(),
                             boxIn.Alpha(), boxIn.Beta(), boxIn.Gamma(),
                             PMEInstanceD::LatticeType::XAligned);
  double evdwrecip = pme_vdw_.computeERec(0, cparamD, coordsD);
  t_recip_.Stop();
  return evdwrecip;
}